When you first run the XMLObjApp, the application will construct a simple class called Root to get you started. Your top-most class does not have to be called Root. In fact, the best name for this class is simply the tag name itself, or "AddressBook" in our example.
Directly beneath the notebook tabs are form fields for the class name and an optional parent class name. The class name must be unique and a valid Python identifier, so don't include any punctuation in the class name.
If you wish to derive the class from another class, you may enter the parent class name in the appropriate field. Don't worry about defining the parent class just yet. We can do that later by editing the parser source code.